Add ecdsa_{read,write}_signature()
diff --git a/include/polarssl/ecp.h b/include/polarssl/ecp.h
index 7bd9bd5..2c0009c 100644
--- a/include/polarssl/ecp.h
+++ b/include/polarssl/ecp.h
@@ -126,9 +126,10 @@
#define POLARSSL_ECP_DP_SECP521R1 25
/**
- * Maximum bit size of the groups (that is, of N)
+ * Maximum size of the groups (that is, of N and P)
*/
-#define POLARSSL_ECP_MAX_N_BITS 521
+#define POLARSSL_ECP_MAX_BITS 521
+#define POLARSSL_ECP_MAX_BYTES ( ( POLARSSL_ECP_MAX_BITS + 7 ) / 8 )
/*
* Maximum window size (actually, NAF width) used for point multipliation.